1. Field of the Invention
The present invention generally relates to collision avoidance systems for vehicles and, more particularly, to enhancements for collision avoidance and warning systems employing in-car resources including air bag deployment systems.
2. Description of the Prior Art
The number of vehicles of all types which are in use is increasing rapidly at the present time. As a result, congestion of airways, waterways and, especially, roadways is also increasing and leading to increased rates and severity of collisions between vehicles. Further, the increase in numbers of vehicles on roadways is increasing more rapidly than it is economically possible to increase transportation infrastructure (e.g. roads, aids to air and water navigation, etc), leading to a need to use available routes, especially roadways, more efficiently and, often, at a higher population density of vehicles than can be safely accommodated by unassisted human operators of vehicles at the present state of the art.
Vehicle collisions are occurring with increasing frequency and severity, often caused by sudden slowing or stopping of traffic flow due to congestion or other collisions or accidents, possibly involving adverse weather conditions. Accidents caused by such conditions often involve multiple vehicles due to the inability of trailing drivers to comprehend and react to sudden changes in traffic conditions and vehicle speed. The injuries, fatalities and financial and economic repercussions are thus greatly and unnecessarily increased.
Accordingly, there has been much recent interest in providing increased protection for vehicle occupants such as energy-absorbing structures and air bags as well as systems which may assist in controlling the vehicle in response to detected conditions. However, systems directed to these very different purposes have necessarily been approached separately and with varying degrees of success.
There are several types of in-vehicle collision avoidance and warning system (IVCAWS) and collision avoidance systems (CAS) currently in use. These systems generally use radar or ultra-sonic emissions to detect vehicle distances, relative velocities and stoppages. Some of these systems also exploit the availability of global positioning systems (GPS) to determine the exact location of vehicles relative to each other to enhance automatic intervention. However, these latter systems are not in general use by the public due to the cost of implementing Such systems using conventional methods while the compromise of effectiveness is unavoidable without substantially universal use. Additionally the complexity of all currently known CAS systems, particularly GPS systems, is slowing industry and public adoption of such technology. Specifically, the use of radar and ultrasonic rear-end collision avoidance systems (RECAS) requires complex sensing equipment and sensing algorithms to predict when a rear end collision may occur or has occurred. The use of ultrasonic emissions to determine vehicle position relative to intersections is also known and, in combination with ground sensors, could provide enhanced collision avoidance protection. However, any CAS system which is not wholly contained within the vehicle, including use of GPS systems, must be included in the transportation infrastructure and carries substantial cost and delays in construction and implementation at a time when resources allocable to construction of transportation infrastructure are often scarce. Further, known CAS systems of all types, have limited effectiveness and operate under the relatively demanding constraint of having their effects limited to the vehicle in which they are installed.
In regard to protection of vehicle occupants, air bags have been the protection device of choice for well in excess of ten years and have been increasingly employed and later required in automobiles and some other vehicles. Initially, air bags were employed for only the driver and for front end impact but later extended to other passengers and other impact directions. While air bags were initially implemented with relatively crude mechanical devices, microprocessors are now currently used to provide for consideration of more input data, beyond an actual impact previously sensed, to determine when an air bag should be deployed.
Such microprocessors, at the present time, are capable of collecting and storing at least a brief history of deceleration characteristics of the vehicle as well as inputs from a speed sensor, gyroscopic sensors and collision sensors to avoid deploying an air bag when deployment is not needed, such as low speed collisions, intense braking of otherwise normal driving and the like. Current air bag deployment processors employ continuous sensor sampling with a storage window of a few milliseconds up to about fifty milliseconds or somewhat longer. If the air bag is actually deployed, the air bag processor is generally arranged to store sensor input for later analysis by law enforcement officials and insurance adjusters to determine the circumstances of the collision although the saved information for such a purpose is very limited. Nevertheless, while the air bag deployment system is wholly contained within the vehicle, at the current state of the art, it has no function in collision avoidance.
Some forms of signaling between vehicles are known and may vary greatly in complexity and functionality from well-known, simple and ubiquitous audible horns to radio communications. For Example, U.S. Pat. No. 6,275,733B1 to Lemelson et al. suggests using radio transmissions from one vehicle to indicate a warning to a driver of an adjacent vehicle or control internal and/or external warning signals or indicators and to signal to police. However, such systems are complex in regard to collision avoidance in the vehicle in which it is installed (this particular system utilizing a dedicated processor and supporting an auto-pilot mode in response to an expanded array of condition sensors of additional types not generally present on currently available vehicles) and do not support collision avoidance systems in other vehicles beyond a very rudimentary level of alerting drivers of adjacent and following vehicles of a dangerous condition and relying on the alerted drivers to take appropriate action.